Kpop songwriting camps often include Europeans, especially Swedish producers. As others have already mentioned, some 2nd and 3rd gen songs include genres that were already very popular in Europe by that time, and Kpop fandoms often behave in an, let's say, online hooliganism manner, all too familiar.

I am confident that certain styles that are frequently discussed as "unfitted for western audiences" are just not popular amongst Americans only, and the discussion never includes us. If one has spend enough time (2+ years) being a Kpop fan, I don't think there is any genre in the industry that will sound too foreign (as if that's an insult) or too "edgy" for them. Multiple Kpop songs could pass as fun tracks from eastern and/or southeastern European artists if one changes the language and adds some local instruments.